Q. I recently saw an ad for a lawsuit involving the diabetes drug Actos. Is it safe for me to continue taking it?

A. That all depends.

Pioglitazone (Actos) and a similar drug, rosiglitazone (Avandia), are in a class of medications known as thiazolidinediones, which are used to treat type 2 diabetes. In August 2012, the U.S. Food and Drug Administration (FDA) approved the first generic versions of pioglitazone.

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Thiazolidinediones — whether used alone or in combination with other antidiabetic agents — can cause or worsen congestive heart failure. For that reason, people with heart failure should not use them, and those with risk factors for heart failure — such as high blood pressure, coronary artery disease, a history of heart attack or irregular heartbeats — should use them with caution. Both Actos and its generic equivalent are labeled with a "black box" safety warning to that effect.

The drugs also carry a warning of a possible increased risk of bladder cancer based on the FDA's analysis of five-year results from an ongoing, 10-year study in California. While the analysis found no overall increased risk of bladder cancer associated with the use of pioglitazone, it did find a slightly increased risk among patients with the longest exposure to — and highest cumulative doses of — the drug. So if you have a history of bladder cancer, or have other risk factors for bladder cancer, you also may want to avoid the drugs.

Still, pioglitazone works so well in older patients that, in my judgment, the benefits outweigh the possible risks for most people. For the reasons mentioned above, if you take pioglitazone, you and your doctor or other health professional should carefully watch for signs or symptoms of heart failure. These include shortness of breath (dyspnea) when you exert yourself or when you lie down, sudden weight gain, or swelling in your legs, ankles and feet. This is especially important when you start taking the drug and whenever there is a change in dosage. Your physician or other health professional should see you on at least a monthly basis until your optimal dose is reached, and after that evaluate your hemoglobin A1c and physical condition at 90-day intervals.

Patients who take pioglitazone also should do a couple of simple self-checks every day. The first is to press a finger into one of their ankles and make sure that there's no indentation left behind when they lift it. If the indentation remains, it's a sign of edema. The second is to make sure they're able to breathe freely when lying down without having to use a pillow to elevate their head. If they should experience trouble breathing, they should get to an emergency room right away.

Fnally, it's important to remember that older patients do not need to keep their blood glucose levels quite as low as younger patients need to. While the American Geriatrics Society recommends that "a reasonable goal for A1c in relatively healthy adults with good functional status is 7 percent or lower," I find that an appropriate target for older people is 7 or to 9 percent.

Although metformin — either alone or with glipizide or glimepiride — is often cited as the treatment of choice for people with type 2 diabetes, it's nearly always the wrong treatment for older patients, who typically lack the ability to flush the drugs out of their kidneys before they accumulate at toxic levels. Because pioglitazone is metabolized in the liver, not the kidneys, it's typically the best way to control type 2 diabetes in older patients.

Ask the Pharmacist is written by Armon B. Neel Jr., PharmD, CGP, in collaboration with journalist Bill Hogan. They are coauthors of Are Your Prescriptions Killing You?, which was published in July by Atria Books.

Remember to go to the AARP home page every day for tips on keeping healthy and sharp, and great deals.

Ask the Pharmacist

Information contained in the Ask the Pharmacist column by Dr. Armon B. Neel Jr. is intended to help individuals and their families become more informed about medication usage and interactions, and be better health care consumers. Any advice or information provided should not be followed in lieu of a personal consultation with a trained medical professional.